<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      .box {
        width: 100%;
        height: 200px;
      }
    </style>
  </head>
  <body>
    <div class="box" id="app">
      姓：<input type="text" v-model="firstName" />+ 名：<input
        type="text"
        v-model="lastName"
      />=
      <span>{{fullName}}</span>
      <br /><br />
      <button @click="changeName">改名卡</button>
    </div>
    <script src="../vue.js"></script>
    <script>
      const app = new Vue({
        el: "#app",
        data: {
          firstName: "",
          lastName: "",
        },
        methods: {
          changeName() {
            this.fullName = "黎小瑶";
          },
        },
        computed: {
          fullName: {
            get() {
              return this.firstName + this.lastName;
            },
            set(value) {
              this.firstName = value.slice(0, 1);
              this.lastName = value.slice(1);
            },
          },
        },
      });
    </script>
  </body>
</html>
